[rtp_rtcp] rtcp::Sli packet moved into own file and got Parse function

webrtc/modules/rtp_rtcp/source/rtcp_packet/sli.cc

 /*
- *  Copyright (c) 2015 The WebRTC project authors. All Rights Reserved.
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
-#include "webrtc/modules/rtp_rtcp/source/rtcp_packet/pli.h"
+#include "webrtc/modules/rtp_rtcp/source/rtcp_packet/sli.h"
 
 #include "webrtc/base/checks.h"
 #include "webrtc/base/logging.h"
+#include "webrtc/modules/rtp_rtcp/source/byte_io.h"
 
 using webrtc::RTCPUtility::RtcpCommonHeader;
 
 namespace webrtc {
 namespace rtcp {
-
 // RFC 4585: Feedback format.
 //
 // Common packet format:
 //
 //   0                   1                   2                   3
 //   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 //  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 //  |V=2|P|   FMT   |       PT      |          length               |
 //  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 //  |                  SSRC of packet sender                        |
 //  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 //  |                  SSRC of media source                         |
 //  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 //  :            Feedback Control Information (FCI)                 :
 //  :                                                               :
+//
+// Slice loss indication (SLI) (RFC 4585).
+// FCI:
+//   0                   1                   2                   3
+//   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+//  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+//  |            First        |        Number           | PictureID |
+//  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+Sli::Macroblocks::Macroblocks(uint8_t picture_id,
+                              uint16_t first,
+                              uint16_t number) {
+  RTC_DCHECK_LE(first, 0x1fff);
+  RTC_DCHECK_LE(number, 0x1fff);
+  RTC_DCHECK_LE(picture_id, 0x3f);
+  item_ = (first << 19) | (number << 6) | picture_id;
+}
 
-//
-// Picture loss indication (PLI) (RFC 4585).
-// FCI: no feedback control information.
-bool Pli::Parse(const RtcpCommonHeader& header, const uint8_t* payload) {
+void Sli::Macroblocks::Parse(const uint8_t* buffer) {
+  item_ = ByteReader<uint32_t>::ReadBigEndian(buffer);
+}
+
+void Sli::Macroblocks::Create(uint8_t* buffer) const {
+  ByteWriter<uint32_t>::WriteBigEndian(buffer, item_);
+}
+
+bool Sli::Parse(const RtcpCommonHeader& header, const uint8_t* payload) {
   RTC_DCHECK(header.packet_type == kPacketType);
   RTC_DCHECK(header.count_or_format == kFeedbackMessageType);
 
-  if (header.payload_size_bytes < kCommonFeedbackLength) {
-    LOG(LS_WARNING) << "Packet is too small to be a valid PLI packet";
+  if (header.payload_size_bytes <
+      kCommonFeedbackLength + Macroblocks::kLength) {
+    LOG(LS_WARNING) << "Packet is too small to be a valid SLI packet";
     return false;
   }
 
+  size_t number_of_items =
+      (header.payload_size_bytes - kCommonFeedbackLength) /
+      Macroblocks::kLength;
+
   ParseCommonFeedback(payload);
+  items_.resize(number_of_items);
+
+  const uint8_t* next_item = payload + kCommonFeedbackLength;
+  for (Macroblocks& item : items_) {
+    item.Parse(next_item);
+    next_item += Macroblocks::kLength;
+  }
+
   return true;
 }
 
-bool Pli::Create(uint8_t* packet,
+bool Sli::Create(uint8_t* packet,
                  size_t* index,
                  size_t max_length,
                  RtcpPacket::PacketReadyCallback* callback) const {
+  RTC_DCHECK(!items_.empty());
   while (*index + BlockLength() > max_length) {
     if (!OnBufferFull(packet, index, callback))
       return false;
   }
-
   CreateHeader(kFeedbackMessageType, kPacketType, HeaderLength(), packet,
                index);
   CreateCommonFeedback(packet + *index);
   *index += kCommonFeedbackLength;
+  for (const Macroblocks& item : items_) {
+    item.Create(packet + *index);
+    *index += Macroblocks::kLength;
+  }
   return true;
 }
 
 }  // namespace rtcp
 }  // namespace webrtc